<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            position: absolute;
            width: 100px;
            height: 100px;
            background-color: pink;
        }
        span {
            position: absolute;
            width: 150px;
            height: 150px;
            display: block;
            background-color: purple;
            margin-top: 200px;
        }
    </style>
</head>
<body>
    <button>点击紫色走</button>
    <div></div>
    <span></span>
    <script>
        function animate(obj,target){
            clearInterval(obj.timer);
            obj.timer = setInterval(function(){
                
            if(obj.offsetLeft >= target){
                clearInterval(timer);
            }else {
                obj.style.left = obj.offsetLeft + 1 +'px';
            }
        },10)
        }
        var div = document.querySelector('div');
        var span = document.querySelector('span');
        var btn = document.querySelector('button');
        animate(div,500);
        btn.addEventListener('click',function(){
            animate(span,1000);
        })

    </script>
</body>
</html>